Google Play Store and App Store APIs provide developers with a simple way to access mobile app data, search functionality, and user reviews. The RapidAPI platform offers a free account option for accessing these APIs, with limited monthly request quotas. The Google Play Apps API can be integrated into Django web applications using the `requests` module in Python, allowing developers to create custom apps searchers and display app details. A basic example of a Django application that uses the API is provided, demonstrating how to implement mobile app searching and displaying app details on a website.